Previous research in our laboratory has indicated that uncomplicated essential hypertensives perform less well on the Wechsler Adult Intelligence Scale and tests of neuropsychological functioning than do normotensive controls. Surprisingly, the most exaggerated differences between hypertensive and normotensive subjects were obtained for a younger rather than a middle aged group of subjects. The young subjects performed better than the older subjects if they were normotensive. However, the young hypertensives performed no better than the older hypertensives. Further, differences in anxiety and depression were larger for the younger subjects than for the older subjects when hypertensives and normotensives were compared at each age group. The purpose of this study is to perform a longitudinal follow-up of the hypertensive and normotensive subjects to determine the extent of age changes in performance for normotensive versus hypertensive subjects and further to continue data collection using a cross sectional design. The latter aspect of the proposed study would permit a study of the effects of high, low and normal plasma renin activity levels on performance of hypertensives as well as an examination of the effects of medication and comparisions of performance for subjects with and without hypertension related pathology. It would also permit a study of the effects of severity of hypertension on performance and a comparison of results of longitudinal and cross sectional findings for a same subjects. It would help us determine the extent to which age x blood pressure interactions are artifacts of the cross sectional design and would extend existing data on the WAIS and hypertension to young and middle aged adults as well as providing a study of neuropsychological test performance in hypertensive subjects for a respectably large number of subjects who have been given a careful medical examination.